[Mike Clasby]

This expression seems to work, on the Start Point (for Lightning, I presume):

yOff = 100 //amount of y offset;
xOff = 0 //amount of x offset;

xAttach = motionTracker(“Tracker 1”)(“Track Point 1”).attachPoint[0];
yAttach = motionTracker(“Tracker 1”)(“Track Point 1”).attachPoint[1];

[xAttach + xOff, yAttach + yOff]

I got it by pickwhipped to the x and y tracker values, then adding in an offset.
If your tracker is tracker 2, then you need to change it to “Tracker 2”. Also, my lightning is on the same layer as the tracking, write back if they are different layers.

[Mike Clasby]

While pedantic additions may be needless, they can be extremely interesting, Thanks.

[Mike Clasby]

I don’t know if this is what you want, but if you want to move the the track points but leave the attach point in the same place (as the original attach point and tracking pointss move off screen), this might help:

Tracking obscured objects in video

https://studio.adobe.com/us/tips/tip.jsp?p=1&id=399&xml=aft6tracking

Here’s an excerpt:

5. Move the search and feature regions. When the tracked object becomes obscured so that the feature region can no longer track it, stop the analyzing process. If necessary, back up a few frames, and then move the feature and search regions to the new feature. Leave the attach point in the same location by pressing Alt (Windows) or Option (Mac OS) as you drag the area of the track point between the search and feature regions, or by dragging the edge of the feature region.

So can you just start tracking and move the track point just before it’s about to leave the screen (on the left), move it to the right while pressing Alt (Windows) or Option (Mac OS), if I’m reading correctly.

[Mike Clasby]

Try wiggling the Opacity. If many layers are involved, either precompose or just add an Adjustment layer and Distort>Trasform>Opacity.

[Mike Clasby]

Slow on the Draw… as usual.

[Mike Clasby]

Pinnacle Image Lunge made a nifty little plugin named Mirage, but you can do a decent job with Fractal Noise and Displacement.

Details:

On a new Black Solid (Comp Size) add Fractal Noise, I used the default setting except animate the Y of FractalNoise>Transform>Offset Turbulence (Y only as you want the heat wave to slowly move upward) with keyframes over time.

Layer>Precomp the Black Solid (Move all attributes) then turn off the eyeball of the precomp.

On the layer you want the heat wave (or on an Adjustment layer, if you want several layer effected) add Distort>Displacement Map. Then choose the Black Solid Precomp layer as the “Displacement Map Layer”. You should be good to go. Adjust Fractal noise settings to get the look you want. Also the “Max Horizontal” And Max Vertical Displacement” in Displacement Map are important for the scale of displacement.

For the complete lowdown on Displacement Maps see Aharon’s three Displacement tuts, click his head and scroll down.

[Mike Clasby]

If your “music quaver” has alpha around it, do Layer>Auto-Trace with Tolerance and Threshold at 1. Then you will have a mask in the newly created AutoTrace layer. M reveals the Mask, Copy the Mask Shape. You can now Paste that into positional properties to make keyframes.

If you don’t have transparency around your quaver, then use the Pen Tool to create a mask that outlines the quaver. Then same thing, use the mask shape (copy) as positional keyframes (Paste). So you could paste that into the Flare Center for Fens Flare. Or the Center for CC Light Rays.

Note: If your position keyframes aren’t where you want them or they’re the same shape but smaller or larger, then you have copied from one sized layer and pasted into a different sized layer. The layers must be the same size for the mask shape to make Positional Keyframes that match correctly.

[Mike Clasby]

When you said, “I can paste that mask shape as positional keyframes on the emitter”, were you meaning an emitter for Particular?

If so you can Alt click the “Position Z” stopwatch, then pickwhip to the Y of the “position XY” (just drag the pickwhip to the Y value only) to get a Position Z expression like this:

effect(“Particular”)(“Position XY”)[1]

Then if you want the Position XY to use it’s own X but ignore it’s own Y, try this expression on Position XY:

value + [0, – effect(“Particular”)(“Position XY”)[1] + 240]

I hacked it with the pickwhip so I’m sure it can be done cleaner. It just tells the Position XY to use it’s original value, then add zero for the X and subtract it’s own Y from itself. The +240 on the end just makes that the new Y, centering it on a frame 480 high. Change the 240 to whatever you want.

If your not talking a Particular Emitter, be a little more spacific, por favor.

[Mike Clasby]

Methinks you need a little Linear Interpolation.

If you used the pickwhip to setup you expression for the Audio Keyframes to drive the Frequency, you probably got an expression like this:

thisComp.layer(“Audio Amplitude”).effect(“Both Channels”)(“Slider”)

And the Frequency will be exactly what the Audio Amplitude Keyframe happens to be at that point in time.

Like Ultimate Bart said, you could put -10 at the end to subtract 10 from the A keyframes, or you could put *2 (times two) to double the values, or /2 to half the values, or you could use Linear Interpolation for max control. Something like this:

amount = thisComp.layer(“Audio Amplitude”).effect(“Both Channels”)(“Slider”);
linear(amount, 0, 25, 0, 15)

amount is equal to your original code. Then as the audio goes from 0 to 25, the frequency will go from 0 to 15 (or the same as Bart’s -10).

If the last line is:

linear(amount, 10, 15, 0, 15)

The audio will only kick in the frequency from 10 to 15 and spread that over the 0 to 15 range.

linear(amount, 0, 25, 0, 150)

Will crank it up by 10, just like adding *10 to your original expression.

For a more detailed expression that is the same as the first linear interpolation I gave you, and kindof explains itself, see this:

amount = thisComp.layer(“Audio Amplitude”).effect(“Both Channels”)(“Slider”);

minAudio = 0;//minimum for Audio Amplitude to kick in
maxAudio = 25; //maximum for audio Amplitude
minValue = 0; //minimum value you want for Frequency/Width/Thickness/etc
maxValue = 10; //maximum value you want for Frequency/Width/Thickness/etc

linear(amount,minAudio,maxAudio,minValue,maxValue)

There are also ease, easeIn and easeOut versions for interpolation.

[Mike Clasby]

CC Ball Action

Really.